Post B4vhMyPGQAovMUehc0 by azonenberg@ioc.exchange
 (DIR) More posts by azonenberg@ioc.exchange
 (DIR) Post #B4vHgE0O3HOoQzXSts by azonenberg@ioc.exchange
       0 likes, 0 repeats
       
       Going live in the next few minutes: ReworkCTF playthrough part 3, actually starting to work through the challenges now that the board is populated and firmware written.https://www.youtube.com/watch?v=wzl7KyQjuBs
       
 (DIR) Post #B4vMllo6Iw9qUIFtui by dl8laq@mastodon.radio
       0 likes, 0 repeats
       
       @azonenberg Hi Andrew, I‘m just a repair technician and learn so much new stuff just by watching your videos! Thank you!
       
 (DIR) Post #B4vhMyPGQAovMUehc0 by azonenberg@ioc.exchange
       0 likes, 0 repeats
       
       Got through a lot today!Done on previous streams:* Challenge 03: Reversed polarity LED* Challenge 13: Missing BGA dogbone, fixed before populating boardDone today:* SM-2: Soldermask touchup* Challenge 01: Small short* Challenge 02: Large short* Challenge 04: Hand solder an 0201* Challenge 05: Hand solder an 01005* Challenge 06: Missing soldermask aperture* Challenge 07: Lifted pad* Challenge 08: Gap in trace* Challenge 09: Inner layer differential pair polarity swapStill pending:* SM-1: Silkscreen text repair* Challenge 10: Missing front-to-back via* Challenge 11: Front-to-back via is shorted to internal layer* Challenge 12: BGA reflow defect* Challenge 14: Missing BGA dogbone on populated board* Challenge 15: Missing pullup resistor* Challenge 16: Via strapping pin to wrong internal planeI expect next stream won't get through quite so many, many of the remaining ones are complex inner layer edits that will take a long time to do.
       
 (DIR) Post #B4vhgJJMvBWthQ7QO0 by azonenberg@ioc.exchange
       0 likes, 0 repeats
       
       Overall the challenge board is working great, all of the problems are behaving as intended so far and my grader firmware is working.I made a two major mistakes:* Removed soldermask from traces but did not tin prior to doing hot-air rework on the surrounding area. This caused heavy oxidation and difficulty tinning traces that would have been nice clean copper otherwise.* Made a large X axis movement on the mill to remove the PCB after lifting the Z axis away from the work area, but not high enough to clear the 0603 capacitor sitting just out of my field of view. This snapped the 250 μm endmill and also cracked the capacitor, requiring replacement of it before I could continue with the originally planned rework.
       
 (DIR) Post #B4viYnceRS6PLR7WQS by azonenberg@ioc.exchange
       0 likes, 0 repeats
       
       But it's been good practice and the difficulty of the harder problems feels about right - doable but very difficult, and on the edge of what I've successfully done in the past. Challenge 14 is uncharged territory, I've done backside milling on 1mm BGAs before but never an 0.8.All of the other challenges are based on things I've done in the past, but in some cases barely pulled off.
       
 (DIR) Post #B4vjwxfWqCWjPJYFZA by azonenberg@ioc.exchange
       0 likes, 0 repeats
       
       Challenge 9 differential pair swap just before overcoating to protect it
       
 (DIR) Post #B50FLGPkfgoNht50gi by j@noise.j-w.au
       0 likes, 0 repeats
       
       @azonenberg UTPPCB?
       
 (DIR) Post #B50FR1rlfqLSK9vvQ8 by azonenberg@ioc.exchange
       0 likes, 0 repeats
       
       @j Lol this is simulating a polarity inversion or just two wires connected wrong on an internal layer. Actually doing a twisted pair like this would be an absurd amount of work
       
 (DIR) Post #B50GAg1BElPVss6Ozg by j@noise.j-w.au
       0 likes, 0 repeats
       
       @azonenberg but of course! Very impressive bodge!Also, sir, with highest respect… your feed is entirely composed of absurd amounts of work (complimentary!) so if an unshielded twisted pcb was a good and useful idea, I don’t believe the effort would deter you 🤣